The alkylation of aromatic hydrocarbons such as benzene is a well-developed art, and one that is practiced commercially using solid catalysts in large scale industrial units. The alkylation of benzene with olefins having from 8 to 28 carbons produces alkylbenzenes that have various commercial uses. One use is to sulfonate the alkylbenzenes to produced sulfonated alkylbenzenes for use at detergents. Alkylbenzenes are produced as a commodity product for detergent production, often in amounts from 50,000 to 200,000 metric tones per year per plant. The alkylation process occurs by reacting benzene with an olefin in the presence of a catalyst at an elevated temperature and pressure.
The performance of aromatic alkylation processes is characterized to a significant extent by the activity and selectivity of the catalyst in the operating environment of the process. Currently available catalysts for aromatic alkylation include those having considerable acidity such as aluminum chloride and zeolites. The characterization of solid materials in terms their acidic properties is described in detail in Satterfield, Heterogeneous Catalysis in Practice, McGraw-Hill, pp. 151-153.
Alkylbenzene, when used for detergents, must meet stringent product specifications to be commercially acceptable. The production of alkylbenzene usually produces a mixture of linear and branched alkylbenzenes. However, due to the lower biodegradability of branched alkylbenzenes, the marketplace transitioned to almost exclusively using linear alkylbenzenes in the production of detergents as they produced a product that was environmentally more acceptable in its relative quickness to biodegrade. One of the problems associated with the production of linear alkylbenzenes is the isomerization of the alkyl group during the production, and therefore reducing the quality of the product. Understanding the reactions that take place and controlling the reaction environment can produce a higher quality product with lower loss of raw materials.